Bread, milk and eggs are just traditional bellwethers of food economy in the US, so they get scrutinized first/most.

eggs went from about ~$3.00 us to ~$8.00 us for a dozen large, that coupled with every other fucking thing that's gone through the roof in unabated unregulated "post pandemic" inflation, hits just about everyone, it hurts, and means or causes fear that just about everyone will stop being able to afford their basic needs

Purely due to circumstance, the price of eggs became an easy, overly simplified economic indicator, and via massive amounts of misinformation/disinformation, somehow an indicator of the Biden administration's efficacy. Eggs were essentially the stand-in for all the complicated and politically inconvenient stuff that willfully ignorant folks don't understand, prefer not to think about, or simply want to deny.

Willfully ignorant people know that grocery prices in general were being affected by inflation, but understanding the causes and recognizing that it was a global phenomenon was not something they were willing to engage in because it was an easy way to demonize and blame Biden.

In my personal experience, when prices spiked last time, these were the people who claimed that eggs were the bulk of their diet because it was the only protein they could afford to eat anymore. That was never true for most, but that's what they claimed as they lamented how they could no longer afford to eat. They also liked to mention the prices of the highest price tier eggs (name brand, organic, fancy stuff, free range, etc) and try to pass that off as the going rate for eggs, despite the fact that they never bought those "premium" eggs prior to the price hike and that the "cheaper" eggs cost significantly less. Also, now that it's happening under their preferred presidential administration, suddenly they are much less vocal (almost completely silent) about the price of eggs. But if forced into a discussion about the topic, they suddenly appear to understand and advocate for the idea that it's caused by factors outside of the president's control. Funny how that works, huh?

On the flip side, most of the folks who are currently bringing up the egg prices are doing so in a satirical sense (even if it's covertly satirical), fully aware that Trump isn't in control of the egg prices. It's just a good way to further demonstrate his supporters' own hypocrisy. Also, it's sort of giving the willfully ignorant people a taste of their own medicine. Probably not terrible effective from that standpoint, but cathartic for the people currently doling it out.

They're part of the consumer price index, a measure of inflation which in turn impacts the fed interest rate. A high rate means a high cost of borrowing which is bad for business (especially small business / start ups).

For most people it just contributes to the cost of living crisis but it has greater implications on the economy as a whole.

Trump has promised a reduction in interest rates this year while nearly all of his policies are designed to worsen inflation in the short term.